Development and Application of a Direct Numerical Method for Reactive Transport Processes in Bubble Systems

The proposed research project is concerned with both the development and application of a Direct Numerical Method for reactive mass transfer at dynamic interfaces in multiple bubble systems. The applicant sets out a hybrid (Lagrangian/Eulerian) method, which \emph{by construction} is intended to fully resolve the sharp concentration gradients occurring for realistic Peclet (Reynolds and Schmidt) and Hatta numbers at the interface by its Lagrangian part, while the method's overall conservative properties inherently results from its Eulerian part. Hence, two crucial properties for a predictive (high-fidelity) Direct Numerical Method for reactive interfacial mass transfer, namely adaptive and sufficient spatial resolution and intrinsic conservation, are conceptually combined to the proposed hybrid method. The development and application of the novel method shall be done within the framework of the free open source C++ library OpenFOAM for Computational Continuum Mechanics. Applying the method by means of Direct Numerical Simulations, the two main objectives of the proposed project are (i) the gain of detailed knowledge and thorough understanding of the complex interplay of two-phase hydrodynamics (bubble interface and bubble wake dynamics), local transport processes as well as transport resistances (diffusive and advective transport of chemical species at dynamic bubble interfaces and within/nearby interfacial boundary layers), and single chemical reactions (local intrinsic kinetics, mass transfer enhancement) by computational analysis, and (ii) the disclosure of the qualitative mechanisms and quantitative relative importance of the influence of above processes near the dynamic bubble interface on the degree of liquid phase utilization, product selectivity and byproduct formation for competitive (mixing-sensitive) prototype reactions within the bubble wake. Moreover, using OpenFOAM the applicant seeks to establish a numerical benchmark among the participating simulating groups providing detailed local data for mass transfer from freely rising single bubbles with and without chemical reaction.


Technische Universtität Darmstadt
Advanced Two-Phase and Interfacial Flow Simulations


Project leader
Dr. Holger Marschall

Project manager
Dennis Hillenbrand M. Sc.